Showing papers on "Angular displacement published in 1995"

Finger operated digital input device

Abstract: A digital input device has a thimble worn on a finger and operated as a mouse for displacement encoding or as a pointer for angular encoding, using a base unit. The thimble can also be attached to a stylus to form a tracing pen or joystick handle. A sensor preferably includes a contact roller at an end of the thimble that rotates with movement over a surface. The sensor emits a signal as a function of incremental displacement of the sensor over a surface, in X and Y directions. The sensor couples to the base unit at a universal joint and the base unit has a cup-shaped contact surface for encoding angular displacement around the universal joint, using displacement of the sensor over the cup-shaped surface. The contact roller is mechanically arranged to pass a coding strip having reflective, transmissive or magnetic stripes before a sensing element. The sensor can be pivoted back on the finger to enable typing. When disengaged from the base unit, the sensor can roll on any surface, and with the stylus can be used as a tracing pen. By scaling the displacement of the input device to equal displacement of a cursor or pointer controlled by software, the input device can be used directly on a display screen.

Continuously rotatable multiple link robot arm mechanism

Abstract: A multiple link robot arm mechanism uses first and second motors capable of synchronized operation to permit movement of the robot arm hand along a curvilinear path as the extension of the hand changes. A motor controller controls the first and second motors in two preferred operational states to enable the robot arm mechanism to perform two principal motion sequences. The first operational state maintains the position of the first motor and rotates the second motor so that the mechanical linkage causes linear displacement (i.e., extension or retraction) of the hand. The second operational state rotates the first and second motors so that a mechanical linkage causes angular displacement of the hand about a shoulder axis. The second operational state can provide an indefinite number of travel paths for the hand, depending on coordination of the control of the first and second motors. An alternative preferred embodiment of the robot arm mechanism substitutes for the hand an end effector structure that has two oppositely extending hands and rotates about a wrist axis. All rotary joints of either embodiment are preferably fitted with rotary fluid slip rings or multiple fluid-passageway spools that permit continuous rotation about any of three axes.

Aiming device using radiated energy

Abstract: An aiming device (or method) which monitors rotational and angular displacement changes with high precision. The detected changes in rotation and/or angular displacement are then used in various operations depending on the implementation. The invention is useful for many different implementations, including a pointing device, a remote control device, and a shooting practice system. Regardless of implementation, the invention utilizes one or more emitters which emit modulated energy signals, and a detector which detects the emitted energy signals. The detected energy signals are processed by a processing unit to determine a point of aim (angular displacement) and a rotation of a detector with respect to the one or more emitters. As a remote control device, the invention enables a user to invoke actions by pointing and rotation of the remote control device. As a shooting practice system, the invention predicts shot placement on a target with high accuracy, while supporting both "live" fire and "dry" fire.

Long-time tails in angular momentum correlations

Abstract: We compare computer simulation results for the angular velocity autocorrelation function (AVACF) of a colloidal particle with theoretical predictions. We consider both spherical and nonspherical particles in two and three dimensions. The theoretical prediction for the long‐time decay of the AVACF in three dimensions is well known, here we also give the two‐dimensional result, along with a sketch of how it was derived. For spherical particles we find excellent agreement between the simulations results and theoretical predictions in both two and three dimensions. We also find that the same expressions apply to the nonspherical particles when the particles have had time to undergo a significant angular displacement. This observation is again in agreement with theory.

Scanning control system for ultrasound biomicroscopy

Abstract: An ultrasonic probe which performs a two-dimensional scan is supported by a mount having a thread which is driven back and forth by a screw along a third axis. When a two-dimensional scan is completed in a first plane, a motor drives the mount along a guide to a second plane for the next scan. The separation between the planes being the same as the resolution in scanning within a plane. A housing having a slot with sidewalls is employed to guide the mount in traveling to successive plane locations along its axis. Means for orienting the housing in angular position and a support assembly provide moveable support to the orienting means so that minimal force is required to position the probe relative to the patient. An "auto-scroll" feature permits the operator to interactively pan through multiple, adjacent two-dimensional planes at programmable speeds and displacements along a third axis. A foot switch provides for hands-free bi-directional scrolling in a "user scroll" mode

Method for coordinating motion control of a multiple axis machine

Abstract: A multiple axis machine includes a plurality of servo-motors that produce movement of a member in at least two axes. The servo-motors are controlled by a computer which runs a simulation of a line shaft power train for producing movement of the member. Specifically, characteristics of a line shaft for powering the machine are defined along with characteristics of a pair of mechanical linkages with dynamically variable kinematics that are driven by the line shaft to produce movement along the two axes. The computer simulates a virtual line shaft using the line shaft characteristics and produces an angular acceleration, an angular velocity and an angular position of the virtual line shaft. The computer also simulates a pair of virtual mechanical linkages with dynamically variable kinematics based upon the linkage characteristics, and based on the angular acceleration, angular velocity and angular position of the virtual line shaft. The simulations produce control signals that operate actuators for each axis of the machine, and produce dynamically variable kinematic feedback force signals which are applied to the simulation of the virtual line shaft to simulate dynamically variable kinematic forces exerted by the mechanical linkages on the virtual line shaft.

Angle of rotation sensor having a counting arrangement with at least two pulser-wire motion sensors providing electrical energy used as a voltage supply

Abstract: An angle of rotation sensor for measuring the angular position of a rotary shaft during more than one revolution consists of a fine angle of rotation sensor linked to the rotary shaft and of a counter. The revolutions of the shaft are all counted without mechanical gears, without an outer voltage supply and without supply batteries, with a simple and economical design. Pulse wire movement sensors supply voltage pulses depending on the rotation of the shaft. The number of voltage pulses is stored in a non-volatile read/write memory.

Vane type angular phase adjusting device

Abstract: Angular phase of a cam shaft of an internal combustion engine is adjusted by changing angular position of a vane rotor in a shoe housing. Each of vanes 2 has a couple of a check valve and a pilot valve which are moving members moving in parallel with the rotation axis to switch on and off oil passages. Since the moving members move in parallel with the rotation axis, the motion thereof is not affected by the centrifugal force caused by the rotation. Further, since the moving members are accommodated inside the vanes, sealing between advancing chambers and retarding chambers which are disposed opposite sides of the vanes can be ensured without increasing the size, particularly the outer diameter, of the device.

Motion transfer mechanism for transferring reciprocol motion to rotary motion

Abstract: A motion transfer mechanism for transferring reciprocal motion to rotary motion comprises at least one driving member having front and rear end portions terminating, respectively, in front and rear ends and mounted to undergo reciprocal motion about a first axis located closer to the rear end than the front end of the driving member. At least one rotary member is mounted to undergo angular displacement about a second axis. An interconnecting member connects the driving member to the rotary member, such that reciprocal motion of the driving member effects angular displacement of the rotary member about the second axis. At least one driven member is mounted to undergo rotary motion in one direction of rotation about the second axis. A transfer device drivingly connects the rotary member to the driven member for transferring angular displacement of the rotary member to rotary motion of the driven member in the one direction of rotation. In this manner, the reciprocal motion of the driving member about the first axis is effectively transferred to rotary motion of the driven member in the one direction of rotation without requiring the application of a substantial force.

Panorama head for optical equipment particularly for photographic equipment

Abstract: A panorama head for positioning optical equipment precisely relative to a system of axes comprises an articulated joint for each axis, each articulated joint including first and second joint elements which are coupled with one another for rotation about the corresponding axis and can be clamped selectively in the preselected relative angular position; each articulated joint comprises a kinematic reduction coupling with first and second coupling elements which are fixed to the first and second joint elements, respectively, during rotation about the corresponding axis and are movable between a position of mutual coupling for precision adjustments and a position of mutual disengagement for quick positioning.

Rotational position sensor with mechanical adjustment of offset and gain signals

Abstract: An angular position sensor is provided with a rotatable magnetic structure that comprises a primary magnet and a secondary magnet. The primary and secondary magnets are adjusted in position relative to each other in order to achieve an adjustability of the gain and offset characteristic of an output signal from a magnetically sensitive component disposed within the magnetic field of the magnetic structure. The primary and secondary magnets are rigidly maintained in position relative to each other and disposed for rotation about an axis of rotation. Each magnet has a magnetic axis extending though its first and second magnetic poles. The two magnetic axes rotate within parallel planes that are each perpendicular to the axis of rotation of the magnetic structure. The gain characteristic of the output signal from the magnetically sensitive component can be advantageously affected by changing the linear distance between the first and second planes in which the first and second magnetic axes of the primary and secondary magnets rotate. The offset characteristic of the output signal from the magnetically sensitive component can be advantageously affected by changing the angular dimension between the first and second magnetic axes of the primary and secondary magnets.

Parallel-structure manipulator device for displacing and orienting an object in a cylindrical work space

Abstract: A parallel structure manipulator device for displacing an object in a cylindrical work space about a predetermined axis (X) includes at least three drive mechanisms (A, B, C) interposed between a base (2) and a moving element (1). Two of the mechanisms (A, B) each include: mover (V) movable along a circular path (L) in a transverse plane perpendicular to the axis (X); a connecting rod (7) extending between the mover and the element (1) and connected thereto by a hinge (8) capable of two-directional rotation; and an attitude transmission member (9) associated with the connecting rod for maintaining the element (1) parallel to the transverse plane. The mechanisms (A, B) act together on the element (1) to define its angular position about the axis (X) and its distance (D) from a notional axis (W) passing through those ends of the connecting rods that are connected to the mover. A third mechanism (C) is free to rotate relative to the base about an axis parallel to the axis (X) and away from the transverse plane. The third mechanism is supported by the base about a pivot axis (H) perpendicular to the axis (X). The third mechanism is thus functionally active to adjust the distance between the element (1) and the pivot axis (H), and to maintain the element (1) pointing towards the axis (X).

Novel Kalman filtering method for the suppression of gyroscope noise effects in pointing and tracking systems

Abstract: A primary cause of degraded performance in pointing and tracking systems is the jitter in the line of sight. This jitter is caused by the residual angular motion of the stabilized platform within the system. A major contributor to this residual motion is the gyroscope noise. Thus, to reduce angular jitter, lower-noise gyroscopes are selected, generally at a premium cost. Another approach is to enhance the accuracy of the gyroscopes electronically (by suppressing measurement noise) before their outputs are fed into the stabilized platform control system. Optimal filtering techniques can be used for this purpose. The goal is to estimate the platform motion so that the calculated value is closer to the actual value than the measurement is. Enhanced performance is obtained at the expense of added complexity, but in many cases this approach may prove to be more economical than resorting to more precise and costly lower-noise gyroscopes. This paper presents a novel Kalman filtering method that provides more accurate angular motion estimates than the measured values. The effectiveness of this method is evaluated through a computer simulation case study. The simulation demonstrates that the new approach yields excellent 3-D angular velocity estimates, very small mean square estimation errors, and over a 5-to-i improvement (in the mean-square sense) over angular velocity measurements obtained from three orthogonal gyroscopes. The enhanced 3-D angular velocity estimates can be fed into the platform stabilization control system rather than feeding raw gyroscope measurements, thus significantly reducing the contribution of gyroscope noise toward the overall jitter in a stabilized platform. This would permit a relaxation on gyroscope noise specifications, which could lead to substantial savings while maintaining the same error budget.

Angular position indicator for remotely displaying the positions of value elements, actuators and the like

Abstract: The present invention relates to an angular position indicator for remotely displaying the positions of elements suitable to assume different angular positions, and, more specifically, valve elements, actuators and the like; the indicator comprises a body which can be coupled to the element the angular position thereof must be indicated or displayed, to the body being associated a display unit which is connected to the element being controlled by a device adapted to transform an angular movement into a rectilinear movement.

Digital position sensor

Abstract: A sensor for providing an indication of the movement of one component of a system with respect to another includes a plurality of discrete electrodes and a common electrode affixed to the non-moving component along the axis of movement of the moving component and a pointer affixed to the moving component also along the axis of movement. As the moving component moves, it positions the pointer at consecutive ones of the plurality of discrete electrodes forming a capacitor structure with each in succession. When interrogated, the capacitor provides a signal indicative of the position of the moving component. The sensor is useful for indicating linear movement, angular displacement and pressure, strain and temperature when adapted to structures which indicate such parameters as a function of displacement. Alternative structures include "Bar Codes" with a laser as a pointer and magnetic stripes with a magnetic read head as the pointer. The output of the sensor may be employed as a feedback signal to a position controller for, for example, a computer-driven machine tool or for a digital hydraulic control system.

Recursive Estimation of Displacement and Velocity in a Cantilever Beam Using a Measured Set of Distributed Strain Data

Abstract: A new form of recursive algorithm to estimate the transverse and angular displacement and/or velocity at any location along the length of a one-dimensional cantilever beam using the strain/strain-rate data measured from a set of sensors distributed along the length of the beam is presented. This is based on the linear spline functions used to approximate the strain distribution in the beam. One of the main applications of this algorithm is in controlling the vibrations in a flexible cantilever beam. To demonstrate its use in such a problem, a linear quadratic regulator (LQR) algorithm is considered and the recursive algorithm stated earlier is used for the state estimation which can be used in conjunction with the state feedback controller. Experimental results for both static and dynamic cases are furnished to validate the proposed estimation algorithm. In the case of static loading, strain gauges are used to measure the strain, while piezoelectric sensors are used in the dynamic case. Results showing th...

Automatic mask alignment in the theta direction using moire sensors

Abstract: Automatic mask alignment in the theta direction using moire sensors is reported. The relation between small angular displacement and linear displacement is clarified. A computer-controlled angular alignment system is developed. A desired alignment position is easily set by a computer. In our experimental condition, angular accuracy of the order of 14*10-7 rad is realized by automatic computer control.

Speed/distance measuring assembly for runner

Abstract: Method and assembly for measuring the speed of or distance covered by a runner. According to the invention, the angular displacement of the foot is measured, and the distance of the trunk from a reference, such as the foot or the ground, is determined. On the basis of these data it is possible to calculate the speed or distance.

Rotation angle measuring system for electric motor shaft

Abstract: Th e rotation angle measuring system provides the absolute angular position of the motor shaft using an angle measuring device (10) coupled to a control unit (11) via an electrical interface. The control unit receives a sine and cosine signal pair dependent on the measured angle from the angle measuring device via an analogue process data channel (8), with a digital parameter channel (9) allowing the control unit to control switching of the process data channel. The sine/cosine signal pair has a high number of periods for each shaft revolution, with incremental counting of the shaft angle, corrected via a synchronisation signal provided by an index marking (15), supplied to the control unit via the parameter channel.

Angular displacement sensor for rotationally reciprocating elements

Abstract: An angular displacement sensor for determining the location of a rotating element such as a power clamp, fixedly attached to the power clamp adjacent the clamp arm. Specifically, the angular displacement sensor includes a rotating portion within a stationary housing, the rotating portion being directly connected to the axle that attaches the clamp arm to the connecting rods driven by the piston. By sensing the position of the rotating portion of the angular displacement sensor, which is directly connected to the axle and thereby rotates in direct proportion to the movement of the clamp arm, the sensor may easily determine the position of the clamp arm.

Device providing real-time orientation and direction of an object

Abstract: Disclosed is a method and apparatus for providing instantaneous real-time information concerning the attitude of an object. When the speed of the object to which the apparatus is attached is known, a real-time three dimensional velocity vector is determinable. The apparatus includes a plate mounted for rotation in a first axis nested within a gimbal means which is also mounted for rotation in a second axis, the first axis and the second axis being orthogonally oriented. The plate may mount a compass, gyroscope or laser. The rate of change of the angular position of the compass, gyroscope or laser is determinable. The rotation of the plate and the gimbal means are ascertained with precision by a novel sensor means. The sensor means determines the rotation by measuring the intensity of radiation (photoemission) passing through a disk with a variable width aperture circumscribed about the disk's circumference. Photodetectors generate a signal based on the intensity of emission which passes through the disk which is processed by appropriate means. A sensor is located to measure the rotation of the plate and a sensor is located to measure the rotation of the gimbal. The signals generated by the two sensors, plus information generated by the compass or gyroscope and the speed of the object will permit a processing means to accurately develop instantaneous changes in attitude and directional vector data. Applications include navigation, aerospace, robotics and defence.

Angular displacement fiber-optic sensor: theoretical and experimental study

Abstract: An optical-fiber sensor based on twist-induced optical activity has been developed for measuring angular displacements at low temperature. The sensing part is composed of a fiber coil rotated between two points, which induces a twist of two sections of fiber. A theoretical study of the evolution of a general input state of polarization in the sensor gave us its main characteristics. Then experimental investigations permitted the construction of a sensor to take angular measurements over a 100-deg range with an accuracy of 0.2 deg. The thermal sensitivity of this kind of sensor is also briefly reported.

Computation of Compression Loads in Twin Screw Compressors

Abstract: The compression mechanism in a twin screw compressor consists of two helical rotors. In this work, a method is presented for computing the forces and moments induced on each rotor due to gas compression. These are defined as the compression loads. The helical rotor surfaces are defined by the end profiles, wrap angle and rotor length. The 3D surface of each rotor is mapped to 2D integration regions. These regions correspond to the surfaces associated with individual compression chambers. The compression loads are computed by integrating the chamber pressure over the rotor surfaces. The integrals are evaluated at incremental values of the rotor angular position. The method is presented and implemented for a specific compressor configuration. The compression loads are resolved to forces at the bearing locations. These bearing forces are presented for operating pressures which represent an under-pressure condition. A frequency analysis demonstrates the rich frequency content of the bearing forces due to the sharpness of the compression loads as a function of the rotor angular position. In addition, it is demonstrated that the moment load about the axis of rotation induced on the female is approximately 12 percent of that induced on the male. Therefore, the female rotor motion approaches that of an idler gear.

Measuring system for determining transverse deflection of a rotary shaft

Abstract: A system for measuring angular displacement of a shaft 11 using a sensor pick-up mounted for rotation with the shaft at two or more angularly spaced locations 16, 17 and 18 wherein the resulting position measurements are processed to produce a measurement of relative displacement of the shaft in a direction transverse to the shaft, two locations being needed to measure displacement in a given direction, and three or more locations being necessary to provide full information about the displacement of the shaft.

Angle of rotation sensor

Abstract: An angle of rotation sensor (1) for measuring the angular position of a rotary shaft (2) during more than one revolution consists of a fine angle of rotation sensor (3) linked to the rotary shaft and of a counter. The revolutions of the shaft are all counted without mechanical gears, without an outer voltage supply and without supply batteries, with a simple and economical design. Pulse wire movement sensors supply voltage pulses depending on the rotation of the shaft. The number of voltage pulses is stored in a non-volatile read-write memory.

Dynamic balancer electronic angle finder

Abstract: An apparatus for determining the placement of mass adjustment on a work piece by a centrifugal balancer includes a device incremented by pulses representing angular displacement of the work piece derived from a device responsive to system drive motor rotation and the drive motor-to-work piece rotation ratio for providing the angular position of the work piece relative to a reference point on the work piece.

Image movement correcting device effecting image movement correction depending on position of center of rotation of angular fluctuation

Abstract: This specification discloses an image movement correcting device for a photographing apparatus for appropriately judging a variation in the amount of image movement correction by the difference in the position of the center of rotation, and effecting accurate image movement correction. Any angular fluctuation of the optical axis of the photographing apparatus is detected by angular displacement detecting means, and when on the basis of the angular fluctuation, image movement correction on a photographing image field is effected by image movement correcting means, the amount of image movement correction by the image movement correcting means is varied in conformity with the position of the center of rotation discriminated by rotation center position discriminating means for discriminating the position of the center of rotation of the angular fluctuation during the photographing by the photographing apparatus.

Register method for carrying out printing processes on rotatably supported articles

Abstract: The printing system is used to print information on the outside surface of a cylindrical object (32), rotated about its axis, via a programme-controlled screen printing machine A marking carried by the object is detected during its rotation about its axis, with the corresponding angular position used as the zero reference point for the object rotation and entered in a memory of the programme control The required printing position is obtained by rotating the object through a defined angle from the stored reference position, with coordinated displacement of the printing screen (18)

Position sensor for contactless detection of defined positions of axially and angularly movable shaft

Abstract: The position sensor has a magnetic displacement sensor (5) whose output depends on a magnet (3) which can be displaced along an axial direction of the displacement sensor. The displacement sensor is arranged with its axial direction (6) effective for the displaceable magnet parallel to the longitudinal axis (4) of the shaft (1). The shaft is moveable along the X-axis and rotates within a defined angle.The magnet is attached to the periphery of the shaft along a helical line for actuation of the displacement sensor. The magnet consists of an elongated body attached to the periphery of a disc (2) and lies along a helical line of constant pitch. The sensor output contains both the axial and angular position information.